Our friend Liz Halloran reports that Mitt Romney "might just win in the South" today as Republicans go to the polls in Alabama and Mississippi to pick between the four remaining candidates for the GOP presidential nomination.

As she writes:

"The latest polls show the former Massachusetts governor locked in a battle supreme in both states with religious conservative Rick Santorum, whose cultural views match up with many voters in the region, and Newt Gingrich, the former congressman from Georgia who has fashioned himself as the Southern candidate." [Rep. Ron Paul of Texas is well behind the others.]

But polling guru Nate Silver at The New York Times' FiveThirtyEight blog has looked at the track record of pre-primary polls in Alabama and Mississippi during recent presidential campaigns and comes away thinking they're "pretty awful."

And why is that? Silver says:

"Social desirability bias — the tendency to provide an answer that you think might seem most acceptable to the stranger on the other end of the line, rather than what you really think. This bias is potentially stronger in cultures that have stronger codes of etiquette, and where people are more self-conscious of the front they present to strangers. This is pertinent in some Asian and Asian-American cultures, for instance. ...

"Etiquette also remains more in tact in the South, and especially in the Deep South, than in most other parts of the country. If so, polls there could encounter similar problems."

Right now, Silver hypothesizes, some Southern Republicans may be telling pollsters that they support Romney because he's the candidate seen "more broadly acceptable and as less offensive, or who have the support of the establishment."

We'll know who's right later, of course. Polls close at 8 p.m. ET in both Alabama and Mississippi.